Our military adopting the Grendel?

[LRRPF52]

In response to the Afghan combat footage:

That is basic react-to-contact...which is more psychological than meant to connect, especially if you look at the nearby mountains he's firing at. The idea behind it is to convince the enemy that they just put their hand in a hornet's nest, rather than an easy target. The more bullets whizzing by their heads, the more likely they are to run away and live to fight another day. Since the Pashtun people have less fear of death than the average human being, I'm not sure how effective our react-to-contact drills really are, and CAS usually deals with these threats.

They know the effective ranges of our shoulder-fired weapons, so far ambushes like this with well emplaced PKM's, mortars, & Dshka's pin the dismounts down. If you have indirect assets on-hand, they can deal with these types of ambushes fairly quickly, but the goal of insurgents or guerrillas is often to get you to overreact, as they collapse into the mud villages, in hopes that you bomb some civilians for the information war campaign.

Since those mountains from which one of the elements engaged from are at least 800m-1.2km away, an M4 in any caliber offers very little. The use of the ACOG to spot and direct mortars was his best bet, but I'll bet the FO was already on it.

[stanc]

Every year, usually in May, the NDIA Small Arms Division puts on a symposium, exhibition and firing demonstration.

http://www.dtic.mil/ndia

I wonder if it might be worthwhile for someone to attend an upcoming meeting, and deliver a presentation on 6.5 Grendel similar to what Gary Roberts did with 6.8 SPC?

http://www.dtic.mil/ndia/2008Intl/Roberts.pdf

Maybe also do a shooting demo with 6.5 Grendel?

[RangerRick]

LRRPF52,

As for pushing E-6's into junior officer ranks you have to understand what an officer's job is. The officer is there to be a representative of civilian control of the military.

No 2nd LT right out of college is going to be as good as an E-7 Platoon Sergeant or even an E-6 Squad Leader. He's there to start the killing and stop the killing.
Military action is the most extreme form of taking people's rights without trial. The officers insure that military action doesn't happen without civilian approval. They are also there to insure that the rules of war and rules of engagement are followed, no matter how much they suck.

A Navy LT with a SEAL team said of his team that they were the finest human beings he had ever known, but he had to watch them like a hawk because they would do ANYTHING to accomplish the mission.

Sometimes you can't do anything and the officer has to say no. That's why it's a more severe offense under the UCMJ to disobey the order of a commissioned officer vs the order of an NCO.

In Special Forces they have made a lot of the team leaders Warrant Officers instead of Captains. They can spend years at the A Team level rather than 3 years like a Captain, who then moves on. That might be a good way to do things for regular units too. But you'd still have to have a way or training junior Commissioned Officers.

The officer system is set up as up or out, you don't stay at a particular level. if you don't get promoted, you have to get out. Non-college educated officers don't fare well at ranks above Captain. Congress has decided they want America's officers highly educated. To make it to Lieutenant Colonel something like 85% have a masters degree or higher.

General Petraeus has a PhD in International Relations from Princeton.

After Company command everything becomes logistics and planning for the staff officers, and strategy and operational art for the Commanders. Being good small unit commanders doesn't help there, except that you know how small units work and what they need.

Lieutenants are apprentices who are there to learn what a small unit is capable of and what it's not and to provide a legal basis for orders. Then they move on.

It sucks for the troops because they always have an inexperienced officer in command but the Platoon Sergeant is there to run the Platoon and keep him from doing anything really dumb.

An E-7 Platoon Sergeant may see a dozen Platoon Leaders in his career. Guys retire as E-6's and E-7's all the time. Some guys just love being a Squad Leader and don't want to be a Platoon Sergeant. They can stay there for a career. Officers can't or you end up with an ossified officer corps.

I know a lot of Platoon Sergeants and First Sergeants who are very proud of the fact that one of the LT's they trained grew up to be a general.

RR

[LRRPF52]

Ranger Rick,

That's probably one of the best explanations of the officer corps I've ever heard summarized in such a fashion. The prior service LT's I had definitely had more control over the Platoons than an IOBC grad though, and they knew what to look for. Inexperienced Lt's actually had to be monitored for excessive use of inappropriate force or stupid actions while deployed in my experience.

Quick example: We had this one Lt. who should have been kicked out of the Army for cheating on the EIB test, at the range estimation station, since he was caught with the distances written on his arm by the EIB cadre. BC backed him up, and he drove on to take some C4 when we were in OIF1, light it on fire (like he had read in the books about Vietnam when guys would use a sliver, not a full 1 1/4lb block, to boil some water in their canteen cup)...then threw it into a pit right near our field ASP for the battalion, where crates of ammo, demo, and pyro were kept.

One of our Combat Engineers, the most sqaured-away 12B E-6 I ever knew, tore into him like there was no tomorrow, explaining that he just nearly took the lives of scores of men, etc. and that they needed to go see the Chain of Command over it ASAP. Lt. was backed again. A weak junior officer is more likely to experience war crimes under his command than a strong prior-service NCO with morals. Don't ask me how I know.

I'm also aware of the officer promotion system, which is dog-eat-dog. In the end, teamwork takes a far lower rung on the pole to CYA and ensure my OER has high ratings. We also are in a situation where there are a lot of senior NCO's who have more college experience than most Captains, with only 4yr degrees. There is the tradition that officers are educated so they can read and interpret orders, which was necessary back in the day, but the level of smart-Aleck enlisted nowadays negates that specific requirement to a large degree. I had this discussion with a 1SG in 19th Group last year, as we waited in-line to shake George Bush's hand.

He has a Master's degree, and had accumulated all sorts of statistics about the educational levels of junior officers, senior enlisted, etc., and even suggested that a prior-service NCO with a 4-year degree could jump to a Company Command position if they had the junior unit leader experience already.

I'm a bit of a throwback to history where I have this idea of a General who lives to win, versus the current line-up of politicians in pristine ACU's, who sound more like Dan Rather than Patton. I would follow Patton to hell and back. Dan Rather wouldn't last my first visceral throat strike...

I've always been of the opinion that we shouldn't place the least experienced guy in a position where responsibility for overall success or failure of the Platoon lies in his hands. The PSG needs to focus on beans, bullets, bandaids, and the combat support aspect of the Platoon HQ in the field, establishing logistics points for distribution of ammo, casualty collection, etc. That is quite separate from the Platoon leader managing the squads, coordinating indirect assets, conducting leader's recons, emplacing ambushes, managing the squads in react to contact, etc.

I can't tell you how many Lieutenants I've seen conduct a leader's recon that was akin to a gypsy caravan, with SAW gunners, AG's, security elements, complete with helmets on. Any local or half-drunk soldier in the area could always hear them from a mile away, whereas any PFC who had been doing recons in a Scout Platoon could tell you right away that the complete lack of stealth with such a large element would compromise them before even leaving the rest of the patrol...but you know what, they can't be told! That's how they did it in Ranger School, and that's how you do it.

In contrast, I've spent literally days on my hands and knees sneaking into denied areas, as a 2-man R&S team. There are so many principles of patrolling commonly violated because it's written in a Ranger handbook that you take X many PAX on a leader's recon. They used to wear PC's in Ranger school, until after the drowning/hypothermia incident in 1994/95? in a Winter class. After that, Kevlars were the norm throughout, since some risk-aversive overlord at unseen levels of the command mandated every possible piece of PPE imaginable.

That then became the norm in light units, since the Lieutenants and Captains didn't know any better. This inability to step back and say, "This doesn't make sense!" really handicaps the leadership system, and translates into a lot of negative value training exercises, with scores of entry-level soldiers who "can't wait to get the **** out of the Army". It really pained me to hear that all the time, since I loved the job, and saw how misguided training was so often, and demoralizing. It's as if a psychological warfare expert from the KGB had penetrated the system long ago, and carefully weaved a convoluted scheme to demoralize warfighters from within the system...

[JASmith]

Sounds like things haven't changed much since my active duty days --

Our classic officer-enlisted model derives from the days when few people could read or write, let alone do more than basic addition and subtraction.

The all-volunteer service seems to have drawn a huge number or highly intelligent and ultimately well-educated folks into the ranks.

Unfortunately the promotion system will thwart even requiring that an individual have prior enlisted service as a first sergeant for entry into either the military academy or OCS. REASON: We seem to have difficulty moving away from numerical rating systems. (Don't blame the computer, its our fascination with numbers!) A numerical system invites box-checkers to do their thing.

Further, it seems that the model perpetuates a class system that victimizes the participants by almost arbitrarily saying that Dick is "better than" Harry or that Janice "knows more" than Jane.

Time for a change...

Speaking of change, it seems that we should at some level be thankful for the current system, because it gives lots of room for debating why the Grendel should or should not be one of our mainstream military cartridges!

[sgt_murf]

Infantry NCO and Officer Courses need to be as violent as practically possible, with maybe 5% classroom time at the most, and a brutal environment that has zero room for pansies, weak-hearted, and the limp-wristed. The corporate career ladder track system with checks and boxes, matrices, and gay terms thrown about like "vignettes" and such needs to get tossed out the window. There is too much glossing over of what you really do, and that is to deploy to foreign soil, locate, fix, close with, and destroy the enemy with fire and maneuver or direct close combat, until the mission is accomplished. This tickle-me Elmo crap has got to go.
...

HOLY crap... tickle me Elmo ...
LR that reminds me of 2 years ago 2 other Senior NCOs, a Captain and I was setting up a joint effort Best Warrior Competition in PA. we had the Ruck march etc etc control element of a fire squad, eval, Weapons trainng Live fire, maintence, board apperances,etc etc you know the drill.
Welllllll this Sister Battalion just had to go to the field with us, during the planning phase I and well as countless Senior NCOs explained to Both Battalion Commanders this was a NCO lead competition with CSMs in charge. Coupled with select Officers to achieve the scoring based on the NCOs Ratings of the competitors. Any way this certain BC (not Mine) had his HQs element there with their full support unit, thus effectively disrupting every aspect of the competition. Several Times the Senior NCOs from my Battalion lit them up for interfering. So the NCO replacing me and I had this great Idea we went to Wal-Mart, at the end during the awards ceromony we Presented that BC a Tickle me Elmo. Funny he was excited about it UNTIL he sat down and My former BC (whom only showed up for the awards ceromony as we requested) leaned over whispered in his ear and explained the message behind it. He was furious, as we was not in his food chain and hat every NCO involved had way over 20 years was basically untouchable. He stated that we as NCOs was unprofessional, to which we responded that surely he was correct and that we should follow his lead and interrupt every training event with a candy @$$ idea that we could devise. Fuming out of the tent my whole senior leadership Field Grades, Senior NCOs, and a few E-6 and below involved burst into laughter and basically rolled on the floor.
(P.S. he left the Tickle Me Elmo on the floor of the Tent, I retrieved it and have it to this day as a reminder)

[LRRPF52]

You can't make this stuff up...

[video=google;2029457706320871566]http://video.google.com/videoplay?docid=2029457706320871566[/video]

We had this embarrassingly worthless BC in 3-325 AIR in the 82nd. He had ordered all the Company CDR's to doctor their Platoon and Company ARTEP Eval boards to say "Trained", when they hadn't, before a Command inspection. Word of this trickled up to General Vines, the Division Commander, who then made sure that our BC's OER reflected thus:

"Places personal career goals above the welfare of his subordinates." He lost his Infantry Branch Assignment, and was sent to Quartermaster, and promptly filed an EO complaint. No matter the occasion, he was always babbling about your "3 feet of space".

I was on a zero range for the SAWs once, when he stopped by to check-up on training. We walked down to the targets, and I noticed a 7.62x39 case on the ground. I picked it up, held it at eye-height between us, and he stared at me like a deer in the headlights. I was expecting him to immediately recognize it, since he had time in Ranger Regiment...nope...it was like a pig staring at a thermometer.

"That's a 7.62x39, sir. Weapons like the AKM, SKS, and RPD eat it..." I said, sounding like a smart a**...unintentionally, and somewhat surprised. (Here's a guy who has been in combat arms units in the Army for the past 18-20 years, and he doesn't recognize the most common foreign weapons cartridge in the world? I had done several foreign wpns ranges up to that time, and I had only been in for 7 years then.

He changed the subject and tried to catch me off guard with some ridiculous question. After the loss of Infantry branch and him being reassigned to some support unit in 18th Airborne Corps, he came back to the battalion area one day. I saw the QM Branch insignia with its prominent star on his left BDU collar, and exclaimed,

"General! Golleee, you made rank FAST sir!!!!" Saluting him smartly, as the redness shone through his melanin-toned skin. He maintained a half-right face so that I couldn't see his silver leaf (which I knew was still there of course).

Anyway, I later learned that his EO complaint helped him get back into Infantry Branch somehow, so he could command troops again...probably made full Bird and deployed with some unfortunate unit as well.

[BluntForceTrauma]

And it's my fear that guys like this somehow get in charge of weapons development and procurement. Or are my fears unfounded?

John

[JASmith]

John,

My experience was that it's a mix. The technical challenges weed out the truly incompetent pretty fast, so many of the O-4's and O-5's are pretty good, with the true dullards usually being retired before making O-6. The retired ones frequently got hired by the Washington contract community, where their "skills" continued to hamper progress.

The good news is that the selection process for O-7 and above seems to work pretty good for the most part. Some of the most intelligent and knowledgeable folks I had the pleasure of meeting with were O-7 and above. There was at least one exception, but he retired as an O-7.

The problem is that the O-4's, O-5's and their civilian counterparts control more of the decision and information generating effort than one would guess. Hence the decision maker rarely sees the ideas the field grade folks didn't like, independent of the merits of the idea.

I can also say that the folks who would cling to a position in spite of an preponderance of information to the contrary did exist, but they are almost always overruled or otherwise ignored. These guys tended to gnash their teeth a lot.

[Irishman]

thank you greyfox, ur absolutely correct and they are still spraying and preying, also the 16 had feeding problems and caused many soldiers to die because of it, the 1st one I was issued jamed, the M14 would rock on, they changed to add rd count, and save weight, the snipers still used the 14, 700 rem,and 70 win, not the 16, same as now, they have made improvements in powder and bullet wt but thet still jam, I am a firarms instructor now in the reserves and they still suck, also if u get 2800 fps from a 120gr bullet, and 2800 from a 69-77 gr bullet if u understand balistics nuf said. ps I live 5min fr AA

[sgt_murf]

....................the snipers still used the 14, 700 rem,and 70 win, not the 16, same as now, .............................

Irish I will disagree with the Winny 70 answer being used... answer is NO it's not being actively fielded could there be some floating about and being used sure just like to this day there is a M1911 somewhere in the inventory in some arms. Is the procurement active from Winchester, not at this time, to my knowledge. The USMC is using basically M700 short actions reworked to Remington 40X standards at Qauntico, not that far from you. The M24 series is built on a long action not short so if the need be to rechamber to 300 is needed simple barrel swap. The M14s are NOT M14s they are reworked to M21 standards aka NM, Designated marksmen (not sniper) are issued worked over M16 series, very few receive the M21. Those M21 as only issued when the food chain chooses that weapon as it is easier to rework a 16 into DMR status than to work a 14 to 21 status. The photos of all those 21s brought out the DMR program based on parts non-availablity lack of proper support etc, etc.
On your assessment about spraying and praying to clearify it a bit conjutures up images of 1 squeeze of the trigger = 20 to 30 rounds out the tube. The M16A2 and up DOES NOT do full AUTO rate as the A1- it is a three round burst weapon. This seems petty I know but it does clearify things for those whom do not vs those of us that do know of this fact.
Do Soldiers aim and use the 3 round burst ---yes--is it useful --- must be or the system would just order semi only versions, my experiance is that yes it is useful. Jamming a lot heck the AK will jam there are no Jam free semi or full auto weapons save a bolt action that won't jam. But as LR1955 has pointed out in several post here even the mighty 6.5G used in the AR platform Jams and has feeding issues just read. That is platform issue, not caliber issues, the ballistics that you also point out will also work out against the 6.5G in a comparision vs other calibers say the 260 Rem or the 6.5x284. Do I understand you bais against the 5.56 sure do and also I know that no matter how well it performs it will always jam in your and greyfox's eyes. I would only offer that since the changes in cartridge in conjuction with introduction of the A2 I personally have seen a better picture than that of a A1 series.
Guys I see your point and understand your view, but most of what I am hearing relates to the Platform about jamming, not terminal performance of the 5.56. Face it if the Platform jams with the 5.56 would it not have same issues with another caliber ?
If we as a group want to see the adoption of the 6.5G lose the AR platform develop something that would actually allow the cartridge to excel. Could this be done and keep the ergos of the M4 -yes. What limits the Grendel is the AR/M16 bolt.
----Added----- Sir your and greyfox's points well founded while it seems like I am on the attack against your statements I assure you your bottom line is not unfounded and within the A1 series I will mostly agree with yours and GreyFox's statements

[JASmith]

The terminal performance of the then standard green tip round at the somewhat longer ranges in Afghanistan appears to have been the motivation for the 6.8 SPC and part of the impetus for thinking about the Grendel in this role.

The Mk262 is given credit for having largely corrected the long range terminal ballistics deficiency when issued to the designated marksman or other similar special purpose roles.

The M8855 A1 was designed and extensively tested to address more than one 5.56 NATO terminal ballistics issue in the hands of the line soldier.

What do anecdotal reports from folks in the field tells us about how well the M855 A1 promise is fulfilled?

If the promise is not fulfilled, then one would assume the development community will need to continue for a search to attain it. The 5.56 cartridge volume has been exploited about as much as it can be within current military production constraints, so that search might take us to another cartridge.

In that case, the Grendel might show very well with appropriate bullets.

[sgt_murf]

Joe,
very, very, valid points, and yes the development of the 5.56 is maxed out, anyone will agree with that. After all this going back and forth I am now becoming more and more convinced that a weapon system needs to be catered around the Grendel itself. One that allows the cartridge more velocity a suitable twist rate for it, yet recoils on par or less than the current weapon and caliber, modular, at or less weight loaded 30rds vs 30rds. This should allow a carbine and a rifle setup with improvements in ergos across the board.
Many will argue for other calibers as well, stating door kickin in Iraq vs longer shots is the 'Stan scenerios, in my opinion the Grendel does show improvement than the current caliber. But it is also my opinion that bashing the current caliber is pointless and causes brass to go deaf. If on the other hand one only points out improvements in the capabilities of the proposed vs the current thus painting a constructive view and alternative it would be well received.
P.S. This is why I sound like a 5.56 Nazi -- bashing the current cartridge also leads to bashing of the proposed cartridge. And disagree with bashing the current cartridge, Heck I prefer the .45 over the 9mm. But I can't argue against it without some going deaf and thinking dude is off and brings up invalid points.
Also with the audience here on this forum a solution that allows the above mentioned capabiliites would not be a issue.

[LRRPF52]

My experience with the M14, even ones right out of the wrappers that we had in Korea, is that it is much less reliable than the AR15 family. The AR15 family is actually one of the top performers in reliability of ALL assault rifles, and my experience with AK variants places the AK on a lower rung of reliability compared to the military M16/M4 series, and I've shot insane volumes, and continue to see high volumes of both systems in training courses with different military and LE organizations. We frequently see FTFire, FTFeed, & double-feed issues with AK Variants, more so than with M4's/AR's.

When I helped with a spendex range burning thousands of round through AK's, several of them were shot into a "Deadline" status, as they were damaged from the mere act of firing. Also, finding enough mags that work in your particular AK can be a task when all the different models, countries, production series, and mag types is considered. The reality is that the Kalashnikov reliability record is a testament of good propaganda, not actual performance. Very few people have the experience with multiple variants of the AK series, and the AR15 series to see this, and most comments about the AK's reliability are made from a very limited scope of use with the different models that are available in the world.

In a dust storm, even the M24 and our breacher shotguns could not have the bolt closed on a cartridge, so the perceptions of AK reliability and any mechanical system to function in extreme dust/sand conditions is unrealistic. Take a sandstorm bath in that region, and your expectations will be brought down to earth.

[sgt_murf]

an old adage I heard years ago still rings true
"the enemies weapons never jams"

On my earlier statement about redesigning the weapon around the Cartridge. The question comes to mind of the Remington/DPMS answer to the .30 RAR they used a modified Bolt and Barrel extentsion humm I don't hear many compliants from their users as few as they are, Food for thought?

[bwaites]

an old adage I heard years ago still rings true
"the enemies weapons never jams"

On my earlier statement about redesigning the weapon around the Cartridge. The question comes to mind of the Remington/DPMS answer to the .30 RAR they used a modified Bolt and Barrel extentsion humm I don't hear many compliants from their users as few as they are, Food for thought?

If you strengthen the bolt, the barrel extension becomes the issue. Strengthen the barrel extension, and another point becomes the weak point. Keep that up, and eventually you end up with a 15-20 pound Carbine. The .30 RAR is a hunting rifle, with inferior ballistics. Bigger bolt, but very limited real options as far as bullet options that work from mags.

Bolts are exspendables, and when a bolt goes, there is really very little damage to the rifle. Maybe a mag is damaged, but other than that, no real damage, generally. It acts like a circuit breaker in an electrical system, and prevents further damage.

I know LRRPF52 thinks that improving or increasing bolt size might be helpful, and I certainly recognize his significantly higher level of experience than my own, but it seems like we might be asking the wrong question when it relates to the AR. The AR works, we actually have very few bolt failures at this stage, and those we have are not catastrophic. I'm not sure that is the right move.

[stanc]

This to me is a bit stunning. Not that I don't believe it, just that even M262 ballistics are getting pretty wimpy past 500 yds, much less 750. At 500 yards it's roughly the same as .22 mag muzzle velocity.

I agree. If they really were making 750-yard, first-round incapacitation shots with Mk262, I think it'd have to be due to shot placement, not wounding capability of the 77gr SMK bullet.

IIRC, Mk262 MV is only 2700 fps or so from a 20" barrel. That would translate to ~2500 fps in the M4 carbine's 14.5" barrel. At distances beyond about 300 yards, MatchKings don't fragment in gel tests.

FWIW, Gary Roberts says that at extended ranges, most all military spitzer bullets produce about the same wound profiles, regardless of caliber. It's at 0-300 yards where differences are noticeable.

FYI:

[sgt_murf]

If you strengthen the bolt, the barrel extension becomes the issue. Strengthen the barrel extension, and another point becomes the weak point. Keep that up, and eventually you end up with a 15-20 pound Carbine. The .30 RAR is a hunting rifle, with inferior ballistics. Bigger bolt, but very limited real options as far as bullet options that work from mags.

Bolts are exspendables, and when a bolt goes, there is really very little damage to the rifle. Maybe a mag is damaged, but other than that, no real damage, generally. It acts like a circuit breaker in an electrical system, and prevents further damage.

I know LRRPF52 thinks that improving or increasing bolt size might be helpful, and I certainly recognize his significantly higher level of experience than my own, but it seems like we might be asking the wrong question when it relates to the AR. The AR works, we actually have very few bolt failures at this stage, and those we have are not catastrophic. I'm not sure that is the right move.

Bill you may be correct in your statement I was really just think out loud but to clearify

Actually I not advocating the .30 RAR just the design of the Bolt, the Extentsion, and the mod to the carrier this would (my opinion without any data or supporting docs) provide a basis for the brass of the cartridge to be the weak link versus the Bolt of the AR platform. Which STILL provides the jamming issue that many have brought up. My short easy answer is use a three lug bolt system do away with the current multi lug setup. After all I just attempting fix the massive jamming issue even though 18 months in Iraq SEVERAL mission clearing IEDs, doing route clearance in sand storms in a asture enviroment my weapon never jammed or misfed. Not to mention that year I spent in the Saudi /Iraqi Desert in the 90s and on G day nooooo issues.
which begs the question why did I clean that thing after every mission and run her dry until ready to go, then light lube critical spots???? ohhhhh yeah I remember first sandstorm in 90 after heavy lubing left the action filled with CLP mud that's why. (and I will not carry a Colt marked weapon period.. any other manufactuer is good to go I consider a Colt badd ju ju personal opinion)

[bwaites]

ANY of the small caliber arms, including .308, are going to punch holes at 750 meters, not have explosive bullet expansion or fragmentation.

300 WinMag and 338 Lapua both still do nasty stuff at that range, but you can't load those into AR 15 mags!

Punching holes works pretty well, as even the results of handgun shootings with .22 long rifle will attest. My reading seems to confirm what cops and ER docs have told me, "guys shot with .22's in the torso don't seem to notice it for about 15-20 seconds, then they just fall over dead." At very close ranges, this is not good stopping power, but at 600 yards or more, its effective. All the small arms cartridges will have that same effect at long range, I suspect. The Mk 262, especially.

All the Grendel does at those ranges is give you a better chance to hit torsos, because it has less wind drift!

[bwaites]

I live in the Eastern Washington desert. We have this little issue with volcanoes which blow up and toss silicate powder into the air every 100 years or so. It's so fine that it will sneak by some auto air filters.

I've never had a dust related jam, either. I've made my Grendel jam, but it took a lot of dirty ammo to do so. I ran a "run 'til it fails test" which I posted on the old board. I didn't clean it for something like 800 rounds before I got a FTF.

I don't understand the concerns with jams in todays versions of the AR. Vietnam era systems were compromised by poor ammo, poor cleaning, poor instruction, and lack of proper care. The guys were told they didn't even have to be cleaned, according to some of the Vietnam era vets I've talked to. They weren't even issued cleaning kits in some circumstances! We need to get over that concern, and move on. Decent maintenance and what we have learned over the last 50 years has fixed that issue!